It’s a very novel idea designed for the Norwegian firm Østensjø, which services marine platforms such as oil and gas rigs. Wired reports that it’s a ‘hotel ship’ that can accommodate and entertain up to 800 workers, and the aim is to make it as stable as possible. The ship has U-shaped water tanks in its hull that create waves internally to counter external ones in the ocean. They produce waves in opposing phase to those acting on the hull, and thus stabilize the vessel.
Air valves at the top of the tanks determine the movement of the water in the tanks. Just as a sailor’s sea legs constantly adjust to the pitch and roll of a boat, the motion of the water in the tanks is calibrated to match the strength of the waves on the sea. That helps the ship stay stable.
There’s an important safety aspect, too, in that it helps the ship to service rigs even in rough seas by enabling the ship to keep its position relative to the rig. The photo (by Marintek) shows how the ship will look when completed in mid-2015. And of course anyone who’s ever been seasick cannot wait for the technology to spread to cruise ships and transatlantic liners…
Filed under: Updates |
Madsen Pirie 
Technology clearly continues advancing steadily in some fields. This book, on pages 42/43 references a patent for such a system in 1910, referred to as Frahm tanks or anti-roll tanks, and subsequently put into common use. The U-tube tanks have benefits at low speeds and stationary, compared to the fin-type stabilisers that are useful only when the ship is underway. Actively pumped U-tank systems followed.
Presumably the century-later use with computer control is something of an improvement, especially where significant periods of ship use have it not underway, though on the open sea and with gangways attached.
Although not annotated as such, the photo is of a scale model of the ship in an evaluation or training tank.
Best regards